1. Field of the Invention
The present invention relates to devices for blending, mixing and/or homogenizing the contents of a bag and, more particularly, of a sterile plastic bag holding clinical samples, for instance used in laboratories, in hospitals, in the food industry, etc.
2. Description of the Prior Art
It is well known to provide sterile plastic bags for holding samples, such as the plastic bag disclosed in U.S. Pat. No. 5,564,829 issued on Oct. 15, 1996 to Lafond. In this patent a disposable sterile plastic bag is disclosed for holding samples in blenders during the mixing thereof, the bag B comprising a two-ply sheet flexible material integrally joined at opposed side edges thereof (or the bag may be made from a tube) and joined at the upper and lower ends thereof respectively by upper and lower heat seals with a sealed sample receiving chamber being defined between the two plastic sheets inwardly of the bag""s side edges and upper and lower sealed ends. Inwardly of the upper seal, there is defined a tear-off line transversely across the two sheets and parallelly to the upper seal thereby forming a detachable strip outwardly of the tear-off line. When the sample is ready to be introduced in the bag, the detachable strip is removed from the bag by pulling it so as to cause rupture of the two sheets at the tear-off line. The bag""s chamber is thus sterile when the sample is introduced therein and the bag and its contents can then be inserted in a blending machine, also called a homogenizer or a mixer. The bag""s sterility does not depend on how the bag is packaged or on the integrity of the packaging""s seal as the bag is itself sterile until the detachable strip is removed therefrom, that is until the bag is ready to be used.
Generally, commercial homogenizers or blenders used in laboratories to mix samples include a casing having a door which is pivoted to the casing and which, when open, reveal a chamber in the casing. In this chamber, there is provided paddles that are adapted to be repeatedly displaced by a motor. When the contents of a bag are to be mixed or blended, the door of the homogenizer is opened and the plastic bag and its contents are inserted into the homogenizer""s chamber and the door is then closed such as to trap the upper end of the bag between the door and the casing while a lower portion of the bag and its contents are located in the chamber. The door, when closed, traps the upper end of the bag and thus firmly secures the same in a generally upright position in the homogenizer. The homogenizer is then switched on and the paddles, in a reciprocating movement, repeatedly pound the plastic bag and thus cause its contents to mix. After the homogenizer has been switched off, the door is opened and the bag is removed therefrom with the blended sample being now appropriately mixed and, for instance, ready for analysis.
In most homogenizers or blenders, the pivotable door cannot be removed from the rest of the blender. Furthermore, any rupture of the bag in the blender causes its contents to flow into the chamber of the blender and possibly onto the surface on which the homogenizer rests. This requires that the blender be extensively cleaned and there are some contamination risks in the laboratory.
To overcome this shortcoming, U.S. Pat. No. 6,267,498 issued on Jul. 31, 2001 15, 1996 to Lafond et al. discloses a blending device for mixing the contents of a plastic bag that comprises a casing defining a mixing chamber in which are disposed paddles or the like for acting on the bag and mix the contents thereof, and having a pivotable door for providing access to the chamber and positioning a bag and its contents in this chamber. The door includes a lower container which extends inwardly towards the casing such as to be located in the casing""s mixing chamber when the door is in a closed position such that spillage resulting from a rupture of the bag in the blending machine is collected in the door""s lower container. The door can be easily and completely disconnected from the casing for facilitating the cleaning thereof, for instance following a collection by the lower container thereof of a spillage.
It is therefore an aim of the present invention to provide an improved device for mixing or blending the contents of a bag and having a collecting member adapted to collect the bag""s contents in the event of a rupture thereof.
It is also an aim of the present invention to provide a spillage collection member adapted to be installed on a blending or mixing device and to receive a bag having a content, such that spillage from the bag while in the device is collected in the spillage collection member.
Therefore, in accordance with the present invention, there is provided a blending device for mixing a content of a bag, comprising a casing defining a chamber and comprising a mixer and a door, in combination with a collection member adapted to receive therein a bag with a content to be mixed by said blending device and adapted to be installed in said blending device, wherein when said collection member and the bag are at least partly positioned in said chamber and said door is closed, said mixer may be operated to act on the bag and cause the content of the bag to be mixed, whereby at least most of the content of the bag spilling therefrom while the bag is in said blending device and said door is closed will be collected by said collection member.
Also in accordance with the present invention, there is provided a collection member for use with a blending device adapted to mix the contents of a bag, comprising an enclosure defining an opening for allowing a bag to be inserted therein and also defining a chamber for receiving the bag, wherein when said collection member and the bag are at least partly positioned in the blending device, said blending device may be operated to act on the bag and cause the content of the bag to be mixed, whereby at least most of the content of the bag spilling therefrom while the bag is in the blending device will be collected by said collection member.
Further in accordance with the present invention, there is provided a method for mixing a content of a bag in a blending device, comprising the steps of:
(a) providing a blending device defining a mixing chamber and having a mixer;
(b) providing a collection member adapted to receive therein a bag with a content to be mixed by said blending device;
(c) positioning said collection member at least partly in said blending device, wherein the bag is positioned in said collection member before step (d) and either before or after step (c); and
(d) operating said mixer such that said mixer acts on the bag and cause the content of the bag to be mixed;
whereby at least most of a spillage from the bag, while the bag is in said blending device, is collected by said collection member.